Overweight/obesity and physical inactivity are two significant predictors of morbidity and mortality from cardiovascular disease (CVD) and other chronic diseases (e.g., diabetes) in Latina adults. These risk factors are modifiable and amenable to lifestyle behavior prevention efforts that focus on promoting a healthy diet and increasing physical activity (PA). The overall goal of this experimental study is to evaluate the effects of a 6-month community-based healthy lifestyle behavior intervention (LSBI) provided by promotoras, designed to improve diet and PA of overweight/obese, middle-age Latino women who are predominantly Spanish-speaking immigrants. The study builds upon formative and feasibility studies implemented using community-based participatory research methods and materials developed in a NHLBI CVD prevention initiative for Latinos. Participants (N=240), ranging in age from 35-64, will be randomly assigned to either the LSBI or a comparable length control condition (disaster preparedness and home safety program). The culturally sensitive LSBI includes 2 months of small group education (based upon Su Coraz[unreadable]n, Su Vida) and a walking club, followed by 4 months of individualized teaching and counseling (ITC). Strategies to promote behavior change, support healthy nutrition and weight loss, and increase PA will be incorporated into the ITC. Data will be collected at baseline, post intervention (6 months after intervention initiation) and at a 3- month follow-up using a combination of clinical and behavioral measures. The primary outcome to be evaluated is change in body mass index (BMI). Secondary outcomes include objective measures of PA (accelerometer readings), blood pressure, cholesterol, blood sugar, waist circumference and self-reported lifestyle behaviors. Selected mediating (stage of change) and moderating variables (social support), derived from the transtheoretical model of behavior change and social ecological model, will be examined in relation to the intervention and program outcomes. Findings will contribute to knowledge about effective communitybased CVD prevention for Latinas involving lifestyle intervention delivered at a grassroots level by promotoras, outside of clinical settings. Understanding also will be enhanced about the influence of interpersonal and environmental factors on adoption of healthy lifestyle behaviors of Latinas.